Intraoperative fabrication of patient-specific moulded implants for skull reconstruction: single-centre experience of 28 cases

Abstract

BACKGROUND Intraoperatively fabricated polymethylmethacrylate (PMMA) implants based on computer-designed moulds were used to improve cosmetic results after hard tissue replacement. To assess the implant's cosmetic and functional results we performed both subjective and objective assessments. METHODS This retrospective analysis was performed using a cohort of 28 patients who received PMMA implants between February 2009 and March 2012. The cosmetic and functional results were assessed using a patient questionnaire. Furthermore an objective volumetric subtraction score (0-100) was applied and implant thickness, as well as gaps and tiers, were measured. RESULTS Patients mainly judged their cosmetic result as "good". Two of the 28 patients found their cosmetic result unfavourable. The functional result and stability was mainly judged to be good. Measurements of implant thickness showed a very high correlation with the thickness of the contralateral bone. Volumetric subtraction led to a median quality of 80 on a scale from 0 to 100. Median gaps around the margins of the implant were 1.5 mm parietally, 1.7 mm frontally and 3.5 mm fronto-orbitally, and median tiers were 1.2 mm, 0 mm and 0 mm respectively. The overall rate of surgical revisions was 10.7 % (three patients). Two patients suffered from wound healing disturbances (7.1 %). The overall complication rate was comparable to other reports in the literature. CONCLUSIONS Implantation of intraoperatively fabricated patient-specific moulded implants is a cost-effective and safe technique leading to good clinical results with a low complication rate. This manuscript has not been published elsewhere in whole or part. 2 AbstractBackground:

Accuracy Assessment of Molded, Patient-Specific Polymethylmethacrylate Craniofacial Implants Compared to Their 3D Printed Originals

“…Studies have quantified and assessed the accuracy of differences between machined and cast PMMA [19], the comparison between manual and automated techniques for cranioplasty plates [20], and the extent of conformity among pressed-titanium sheet implants on CRD contours [21]. Other studies examining 3D printed templates and PSIs often depict the accuracy or the evaluation of cosmetic outcomes based on CT scans, as well as patient questionnaires to obtain objective and subjective assessments [8,22]. Therefore, to investigate the outcome quality of a PSI in a more objective manner, the present study was conducted.…”

“…The use of synthetic or alloplastic materials, such as alloys (Titanium [Ti]), ceramics (hydroxyapatite [HA]), acrylics (polymethylmethacrylate [PMMA]), or polymers (polyetheretherketone [PEEK]), has become increasingly popular. These alloplastic materials are now used regularly to reconstruct CRDs in a sufficiently cosmetic manner [6,8].…”

Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile

“…In Medicine, PMMA bone cement grafts have been used in cranioplasty, with high stability and a low complication rate. 28,29 PMMA grafts are biocompatible, 30 very stable, and inert over time, and are considered a cost-effective and safe technique. 28,29 In Dentistry, PMMA has also been used in the maxillofacial area for tumors, trauma, and TMJ ankylosis.…”

What happens to the bone flap? Long-term outcome after reimplantation of cryoconserved bone flaps in a consecutive series of 92 patients

“…Those won't even need to be inferior towards commercial products regarding their cosmetic results and complication rate as we were recently able to show [17].…”